This invention relates to an oral composition which can prevent periodontal disease through suppression of the intraoral colonization of the causative bacteria of periodontal diseases such as Bacteroides gingivalis. More specifically, it relates to an oral composition which coprises a specific type of antibody obtained by immunizing a mammal with at least one antigen selected from the group consisting of periodontal causative bacteria, their pillus and capsule fractions. The composition ensures the stability of the antibody over a long period of time, so that the efficacy of the antibody is reliably prolonged.
There are many people who have periodontal disease such as gingivitis and periodontitis. The rate of such disease in adults is especially on the increase. Prevention of periodontal diseases will be an important problem in the future for an increasing number of aged persons.
Periodontal disease is primarily caused by bacteria existing in accumulated plaque in periodontal pockets. A healthy periodontal pocket is usually composed of an overwhelming amount of gram positive bacteria, while the amount of gram negative bacteria increases with the progress of the periodontal disease. Bacteroides gingivalis, Fusobacterium nucleatum, Eikenella corrodens, Actionobacillus actinomycetemcomitans and so forth are primarily listed as such gram negative bacteria. In the focal regions of adult patients with severe periodontal disease, gram negative bacteria are detected in most cases among which Bacteroides gingivalis is separated in specially high frequency. In many of these cases, the titer of anti-Bacteroides gingivalis antibody in the serum of the patient also increases. In addition, it has been demonstrated that the inoculation of an animal with Bacteroides gingivalis aggravates periodontal inflammation. These results indicate that Bacteroides gingivalis plays an important role in the development of periodontal diseases. Bacteroides gingivalis adheres to periodontal mucosa by means of its pili and capsule existing on the surface of its bacterial body, thereby proliferating and badly influencing the periodontal region.
In addition, Actinomyces viscosus, which is a gram positive bacterium, is detected from the focal regions of periodontal diseases and is known to be a periodontal causative bacterium.
In order to prevent periodontal diseases, the inhibition of the colonization or suppression of the proliferation of the periodontal causative bacteria such as Bacteriodes gingivalis in the mouth is effective and bactericides are now mainly used for that purpose. In some more specific methods, the inhibition of the colonization of the periodontal causative bacteria in the mouth is attempted by using a vaccine. However, since the whole bacterial body is used as an active vaccine directly injected into the living human body in all of these methods, they have problems in terms of both effect and toxicity.
Under these circumstances in the art, we made studies of a highly safe method which can effectively inhibit the colonization of Bacterides gingivalis in the mouth to more reliably prevent periodontitis. As a result, we found that an antibody in blood or milk, which was obtained by immunization of mammals with Bacteroides gingivalis, its pilus or capsule fraction as an antigen, suppressed the colonization of Bacteroides gingivalis in the mouth. Based on the above finding, we proposed an oral composition comprising the antibody (the U.S. patent application Ser. No. 686,904).
However, it was also found that these antibodies could not always be stably kept in the oral composition, along with the problem that the antibodies were liable to be deactivated by the presence of anionic surface active agents such as sodium lauryl sulfate.